The invention of the bow and arrow allowed users to shoot projectiles more rapidly and more
accurately than with the traditional spear.

A new theory argues that this innovation resulted in more than just a technological revolution.
It also had profound social consequences wherever the bow was adopted.

Stony Brook University biologists Paul Bingham and Joanne Souza developed the “social-coercion
hypothesis” as an explanation for the rise of social complexity. They recently outlined their work
in the journal
Evolutionary Anthropology.

According to this idea, the introduction of a more-effective weapon system gave social groups a
safer, more-reliable way to coerce uncooperative individuals to support the efforts of the group or
to seek another one somewhere else.

This, in turn, allowed social groups to grow larger without the previously inevitable
splintering into rival groups based largely on family loyalties. In violent conflicts, members of
larger groups would have an evolutionary advantage over members of smaller groups. As a result,
larger groups requiring increased levels of social complexity would proliferate.

It’s an intriguing idea, but is there evidence to support it?

John Blitz, an archaeologist at the University of Alabama, and Erik Porth, a grad student there,
reviewed the data for eastern North America and say there is. They report the results of their
study in the same issue of
Evolutionary Anthropology.

According to Blitz and Porth, the bow and arrow were adopted in the Ohio Valley between A.D. 300
and 400. During this period, large spear points were replaced by smaller arrowheads. The result,
however, was not an increase in social complexity. Far from it.

This period marks the collapse of the Hopewell culture, a far-flung network of cooperating
communities that gathered periodically at monumental ceremonial centers, such as Newark’s sprawling
earthworks.

You might think that means the social-coercion theory bites the dust.

Not so, according to Blitz and Porth. They argue that the introduction of the bow increased the
efficiency of individual hunters so much that they no longer needed to cooperate in large-scale
game drives. With one big reason for large gatherings eliminated, the precocious social complexity
of the Hopewell disintegrated.

But that’s not the end of the story. In the wake of the Hopewell collapse, the population
actually increased, and villages began to pop up across the Ohio valley. In time, these communities
began to compete with one another.

Around A.D. 600, a more-sophisticated arrowhead appeared in eastern North America and rapidly
replaced the older version. This was followed by an even bigger boost in population, which
increasingly became concentrated in large villages.

These villages often were surrounded by a palisade or a ditch, and bodies buried at these sites
frequently have arrowheads lodged in their bones, indicating that the bow and arrow were used as
military weapons.

Blitz and Porth conclude that the new social roles that arose out of the need for community
defense laid the foundations for the rise of social complexity culminating in the elite chiefs who
ruled the Mississippian metropolises, such as Cahokia in Illinois.

These data suggest that Bingham and Souza are right about the far-reaching effects such an
important technological innovation could have on all aspects of a society.

Bradley T. Lepper is curator of archaeology at the Ohio Historical Society.